A laundry treatment apparatus capable of drying laundry dries wet laundry by applying dry air. The laundry treatment apparatus includes an air channel and a drum for accommodating laundry. The laundry treatment apparatus includes a heater for dehumidifying and heating air flowed into through the air channel and a fan disposed on the air channel and putting pressure for flowing of air. It is also known that a conventional laundry treatment apparatus includes a filter disposed on the air channel and filtering foreign substances from air.
The laundry treatment apparatus is classified into a laundry treatment apparatus equipped with an exhaust type drying system and a laundry treatment apparatus equipped with a circulation type drying system in accordance with how air to be supplied to laundry is treated after exchanging heat with the laundry. Moreover, there is another laundry treatment apparatus equipped with a hybrid system in which air inside a drum is partially exhausted, and the remaining air is re-supplied to the drum through circulation.
The air channel of the laundry treatment apparatus equipped with the exhaust type drying system or the hybrid system includes an exhaust duct which provides a passage for exhausting of air inside the drum outside.
Meanwhile, there is a case where the laundry treatment apparatus is used in an environment in which a system duct connected to multiple exhaust ducts is provided. In this case, multiple laundry treatment apparatuses share one system duct. In this environment, all of the air discharged from multiple laundry treatment apparatuses is guided through the one system duct. For example, the system duct which is connected to multiple laundry treatment apparatuses is installed in a place such as a laundry shop which commercially uses the laundry treatment apparatus. As another example, there is a case where the system duct which is connected to multiple laundry treatment apparatuses which are disposed at each room or layer such as in a dormitory or the like having multiple rooms or layers is installed.